js/magic-bird/imgs/extracted-1688-map/MapParts/towns/96.png

# Example showing file syscalls.
#
# Create a file, open it for writing, write a character to it, close it, open
# it for reading, read a character from it, close it, delete it, and return
# the character read.
#
# To run:
#   $ ./subx translate init.linux examples/ex7.subx -o examples/ex7
#   $ ./subx run examples/ex7
# Expected result:
#   $ echo $?
#   97

== code
#   instruction                     effective address                                                   register    displacement    immediate
# . op          subop               mod             rm32          base        index         scale       r32
# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes

Entry:
    # creat(Filename)
    bb/copy-to-ebx  Filename/imm32
    b9/copy-to-ecx  0x180/imm32/fixed-perms
    e8/call  syscall_creat/disp32

    # stream = open(Filename, O_WRONLY, 0)  # we can't use 'fd' because it looks like a hex byte
    bb/copy-to-ebx  Filename/imm32
    b9/copy-to-ecx  1/imm32/wronly
    ba/copy-to-edx  0x180/imm32/fixed-perms
    e8/call  syscall_open/disp32
    # save stream
    bb/copy-to-ebx  Stream/imm32
    89/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # copy eax to *ebx

    # write(Stream, "a", 1)
    # . load stream
    bb/copy-to-ebx  Stream/imm32
    8b/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # copy *ebx to ebx
    # .
    b9/copy-to-ecx  A/imm32
    ba/copy-to-edx  1/imm32/size
    e8/call  syscall_write/disp32

    # close(Stream)
    # . load stream
    bb/copy-to-ebx  Stream/imm32
    8b/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # copy *ebx to ebx
    # .
    e8/call  syscall_close/disp32

    # stream = open(Filename, O_RDONLY, 0)
    bb/copy-to-ebx  Filename/imm32
    b9/copy-to-ecx  0/imm32/rdonly
    ba/copy-to-edx  0x180/imm32/fixed-perms
    e8/call  syscall_open/disp32
    # . save Stream
    bb/copy-to-ebx  Stream/imm32
    89/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # copy eax to *ebx

    # read(Stream, B, 1)
    # . load stream
    bb/copy-to-ebx  Stream/imm32
    8b/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # copy *ebx to ebx
    # .
    b9/copy-to-ecx  B/imm32
    ba/copy-to-edx  1/imm32/size
    e8/call  syscall_read/disp32

    # close(Stream)
    # . load stream
    bb/copy-to-ebx  Stream/imm32
    8b/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # copy *ebx to ebx
    #
    e8/call  syscall_close/disp32

    # unlink(filename)
    bb/copy-to-ebx  Filename/imm32
    e8/call  syscall_unlink/disp32

    # exit(b)
    # . load b
    bb/copy-to-ebx  B/imm32
    8b/copy                         0/mod/indirect  3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # copy *ebx to ebx
    #
    e8/call  syscall_exit/disp32

== data

Stream:
    0/imm32
A:
    61/imm32/A
B:
    0/imm32
Filename:
    2e 66 6f 6f 00 00 00 00
#   .  f  o  o  null

# . . vim:nowrap:textwidth=0
ofs	hex dump	ascii
0000	89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52 00 00 00 1e 00 00 00 1e 08 06 00 00 00 3b 30 ae	.PNG........IHDR.............;0.
0020	a2 00 00 02 0a 49 44 41 54 78 da ed d6 5f 44 9d 71 1c c7 f1 fe 8d 46 36 a2 65 a5 75 d5 58 44 51	.....IDATx..._D.q.....F6.e.u.XDQ
0040	96 95 52 9a d2 55 94 31 8b 34 4d a2 ab 34 4b 36 d1 cc 12 d9 48 a2 d4 4d 8c 19 29 a6 89 b2 31 65	..R..U.1.4M..4K6....H..M..)...1e
0060	23 9b cc ba d9 92 74 51 aa 8b 2e 6a ad b5 ce d9 fb cb 27 1e c7 a9 76 ce 73 4e e7 e6 fc 78 f1 9c	#.....tQ...j......'...v.sN...x..
0080	e7 df e7 fc 9e df ef f7 7d 9e 98 98 68 8b b6 ff 6f c3 a8 8b 44 f0 12 1e 9e 77 68 3c d6 d1 12 89	........}...h...o...D....wh<....
00a0	1e af a1 28 12 c1 57 7c 7e 57 21 25 5c 61 09 c8 43 25 4a 50 8e 5a b4 61 2e 9c 8f de 26 d3 02 be	...(..W\|~W!%\a..C%JP.Z.a....&...
00c0	60 14 6f f1 03 7f 70 88 01 c4 86 3a f4 32 26 31 8f 07 8e fd 37 e0 c1 36 ea c3 d5 63 0b fe 88 0a	`.o...p....:.2&1....7..6...c....
00e0	c7 be ab 0a fe 85 bb e1 08 4d c7 2c be a1 03 89 3e c1 7f d1 1c ea d0 3b 58 d4 12 b2 9e ed a1 5b	.........M.,....>......;X......[
0100	c7 92 15 6c 9e 84 2a b0 11 d3 0a fc ad 5e 79 34 91 c6 b5 a4 32 e0 c5 01 fa 54 5c 5c 3f da 4f d8	...l..*......^y4....2....T\\?.O.
0120	51 f0 0c 5e 69 46 1f 61 43 7f ac 4e c1 b6 ef 85 db d0 38 0c e9 91 5a 4d 7e 8e 62 a4 6a dd 7e 57	Q..^iF.aC..N......8...ZM~.b.j.~W
0140	d0 04 fa b5 6d e1 3d 6e 83 b3 75 33 d3 ee e7 78 1a b6 f0 1e 63 d8 d7 10 74 b9 0d ce 55 a8 8d 6f	....m.=n..u3...x....c...t...U..o
0160	d6 09 e7 ac e2 33 5e e3 a7 ce 7f e4 26 d4 ea ed 63 dd 68 0a 99 a7 04 4f 69 18 e6 34 f1 3a 83 0d	.....3^.....&...c.h....Oi..4.:..
0180	7d a9 5e 6c 6b e6 da d2 b9 ef e7 bc 8b 3a e7 99 8a c9 b4 ce ef 0e 26 f4 92 c6 cd 4a e2 20 7a b1	}.^lk........:........&....J..z.
01a0	8b 15 9f b1 ab 55 6f 2d e8 1e ae 39 82 83 fe 30 78 a7 90 7c 24 69 5d 2e 29 dc 5e 0a 23 f8 aa 97	.....Uo-...9...0x..\|$i].).^.#...
01c0	c2 1b dc c4 2d 6c 6a 72 8d e9 ba 0b 81 84 5e d7 cd 3b f5 ca b3 8a d4 aa 8a e5 d1 72 f1 3a ea b2	....-ljr......^..;.........r.:..
01e0	2d 9d 06 fd b9 e3 63 cb fa fd 14 35 ba c7 89 ed 36 3e 68 32 79 fc f0 3a 0a 84 33 fc 98 ef fe 23	-.....c....5....6>h2y..:..3....#
0200	c7 f6 99 c5 c2 5e 6d 05 2a f8 39 da ce d5 4b bf 49 93 c8 26 59 b5 1e 6f b6 ae c9 d1 b0 94 ea a3	.....^m.*.9...K.I..&Y..o........
0220	a0 0c 85 a7 ac 84 80 5b 62 f4 6b 3e d0 f6 0f 99 f2 99 96 d7 10 93 15 00 00 00 00 49 45 4e 44 ae	.......[b.k>...............IEND.
0240	42 60 82	B`.